001/* Compare two Double objects with a fuzzy threshold.
002
003 Copyright (c) 2006-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_2
025 COPYRIGHTENDKEY
026 */
027package ptolemy.actor.util;
028
029import java.util.Comparator;
030
031///////////////////////////////////////////////////////////////////
032//// FuzzyDoubleComparator
033
034/**
035 Compare two Double objects with respect to a fuzzy threshold.
036 The threshold is set by setThreshold(). If the difference of the
037 two double number is less than the threshold, then they are considered
038 equal. The default value of the fuzzy threshold is 1e-10.
039 <p>
040 After Ptolemy II 4.1, this class is not used any more. Use
041 {@link GeneralComparator} instead.
042
043 @author Jie Liu
044 @version $Id$
045 @since Ptolemy II 5.2
046 @deprecated As Ptolemy II 4.1, use GeneralComparator instead.
047
048 @Pt.ProposedRating Yellow (liuj)
049 @Pt.AcceptedRating Yellow (hyzheng)
050 */
051@Deprecated
052public class FuzzyDoubleComparator implements Comparator {
053    /** Construct a FuzzyDoubleComparator. The compare threshold is
054     *  1e-10
055     */
056    public FuzzyDoubleComparator() {
057        _threshold = 1.0e-10;
058    }
059
060    /** Construct a FuzzyDoubleComparator with the given threshold.
061     *  @param threshold The threshold
062     */
063    public FuzzyDoubleComparator(double threshold) {
064        _threshold = threshold;
065    }
066
067    ///////////////////////////////////////////////////////////////////
068    ////                         public variables                  ////
069
070    /** Compare two objects according to a threshold.
071     *  Return -1 if first &lt; second - threshold/2;
072     *  return 1 if first &gt; second + threshold/2;
073     *  return 0 otherwise.
074     *
075     *  <p>If any of the argument is not a Double object, a ClassCastException
076     *  will be thrown.
077     *  @param first The first Double object.
078     *  @param second The second Double object.
079     *  @return The comparison result, -1, 0, or 1.
080     */
081    @Override
082    public int compare(Object first, Object second) {
083        double firstValue = ((Double) first).doubleValue();
084        double secondValue = ((Double) second).doubleValue();
085
086        if (firstValue < secondValue - _threshold / 2.0) {
087            return -1;
088        } else if (firstValue > secondValue + _threshold / 2.0) {
089            return 1;
090        } else {
091            return 0;
092        }
093    }
094
095    /** Return the fuzziness threshold.
096     *  @return The fuzziness threshold.
097     *  @see #setThreshold(double)
098     */
099    public double getThreshold() {
100        return _threshold;
101    }
102
103    /** Set the fuzziness threshold. The threshold is always positive.
104     *  If the argument is negative, then its absolute value is taken.
105     *  @param threshold The threshold.
106     *  @see #getThreshold()
107     */
108    public void setThreshold(double threshold) {
109        _threshold = Math.abs(threshold);
110    }
111
112    ///////////////////////////////////////////////////////////////////
113    ////                         private variables                 ////
114
115    /** The threshold that controls the fuzziness. Default value 1e-10. */
116    private double _threshold;
117}